Shave gel compositions

ABSTRACT

Heated, post-foaming shave gels are provided. Post-foaming shave gels that include a non-ionic emulsifier system are also provided. In some implementations, the non-ionic emulsifier system includes one or more fatty alcohol ethoxylates.

[0001] This invention relates to post-foaming shave gel compositions.

BACKGROUND

[0002] Currently, a widely used form of shaving preparation is the type referred to as a post-foaming shave gel. These post-foaming shave gels are now well-known and have been described, for example, in U.S. Pat. No. 2,995,521 (Bluard), U.S. Pat. No. 3,541,581 (Monson), U.S. Pat. No. 4,405,489 (Sisbarro), U.S. Pat. No. 4,528,111 (Su), U.S. Pat. No. 4,651,503 (Anderson), U.S. Pat. No. 5,248,495 (Patterson), U.S. Pat. No. 5,308,643 (Osipow), U.S. Pat. No. 5,326,556 (Barnet), U.S. Pat. No. 5,500,211 (George), U.S. Pat. No. 5,560,859 (Hartmann) and U.S. Pat. No. 5,858,343 (Szymczak). Such compositions generally take the form of an oil-in-water emulsion in which the post-foaming agent, generally a volatile (i.e., low boiling point) aliphatic hydrocarbon, is solubilized in the oil phase, and the water phase comprises a water-dispersible soap or interrupted soap component. The product is generally packaged in an aerosol container with a barrier, such as a piston or collapsible bag, to separate the post-foaming gel from the propellant required for expulsion of the product. The product is dispensed as a clear, translucent or opaque gel that is substantially free from foaming until it is spread over the skin, at which time it produces a foam lather generated by the volatilization of the volatile hydrocarbon foaming agent.

[0003] Users of wet-shave razors generally appreciate a feeling of warmth against their skin during shaving. The warmth feels good, and also causes the user's skin to hydrate and beard to soften, resulting in a more comfortable shave.

[0004] Various attempts have been made to provide a warm feeling during shaving. For example, shaving foams have been formulated to react exothermically upon release from the shaving canister, so that the foam imparts warmth to the skin, e.g., as described in U.S. Pat. No. 3,341,418.

SUMMARY

[0005] The invention features heated post-foaming shave gels. The shave gels are heated after delivery by an exothermic reaction that occurs when two components of the shave gel that are separated prior to delivery are mixed during or after delivery.

[0006] Preferred post-foaming shave gels have a non-ionic emulsifier base, rather than a soap base. By “non-ionic,” we mean that there is no more than 1% by weight of any ionic material in the emulsifier base. Preferably, there is no more than 1% by weight of any ionic material in the gel compositions. Thus, the preferred shave gels are substantially free of soaps and of anionic surfactants. The non-ionic, soap-free formulation is compatible with and stable in the presence of the actives that are used to generate the warm sensation. The non-ionic base may also offer additional advantages such as alleviating the problems associated with soap-based products. The shave gels include an emulsifier system that includes fatty alcohol ethoxylates with relatively longer and shorter polyethylene oxide chains, as will be discussed below.

[0007] In one aspect, the invention features a shaving gel including a post-foaming shave gel base, and heating reagents selected to provide an exothermic reaction during use of the shaving gel.

[0008] The post-foaming shave gel base may include an oil-in-water emulsion including a non-ionic emulsifier. The heating reagents may include an oxidizing agent, e.g., a peroxide, and a reducing agent, e.g., selected from the group consisting of thiosulfate and sulfite compounds, compounds with a thiourea backbone, and mixtures thereof. The shave gel may be provided in the form of an oxidant component and a reductant component that are maintained separate until the shave gel is dispensed by a user.

[0009] The non-ionic emulsifier may include a fatty alcohol ethoxylate with a relatively long polyethylene oxide chain, and may further include a fatty alcohol ethoxylate with a relatively shorter polyethylene oxide chain. Preferably, the fatty alcohol ethoxylate with a relatively long polyethylene oxide chain and the fatty alcohol ethoxylate with a relatively shorter polyethylene oxide chain are provided in a ratio in the range of from about 1:1 to 1:3. The shaving gel may also include an emollient. Each emulsifier's hydrophilic (water-loving) part includes polyhydric alcohols and polyoxyethylene chains. Typical lipophilic parts may be long hydrocarbon chains, as in the fatty acids, a cyclic hydrocarbon, or a combination of the two. Chiefly hydroxyl groups and ether linkages from polyhydric alcohols and polyoxyethylene chains generate the hydrophilic action.

[0010] In another aspect, the invention features a post-foaming shave gel product including, a two-component container having two separate chambers; disposed in one chamber, an oxidant component comprising a first post-foaming shave gel base including an oxidizing agent, and, disposed in the other chamber, a reductant component comprising a second post-foaming shave gel base including a reducing agent.

[0011] Generally, the first and second post-foaming shave gel bases are provided in the form of oil-in-water emulsions. The first and second post-foaming shave gel bases may include a non-ionic emulsifier.

[0012] Some implementations exhibit one or more of the following advantages. The shave gels provide a pleasant, warm feeling to the user before and during shaving, in combination with the aesthetic properties of a post-foaming gel. The heating effect of the gels helps to hydrate a user's beard and prepare the beard for shaving, improving user comfort. The gels are shelf stable, and dispense from their packaging in an attractive, aesthetic gelled form. After dispensing, the gels provide a smooth, creamy, stable lather that develops quickly when the gels are spread over the skin. The lather remains creamy and stable when the gel is heated. The gels provide desirable performance properties such as lubricity and skin-friendliness, which are maintained during and after heating. The chemistry of the heating system that is used to heat the gel is safe for use on the skin and does not irritate the skin.

[0013] Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.

DETAILED DESCRIPTION

[0014] Preferred post-foaming shaving gel compositions include water, a system of water-soluble polymers, a non-ionic emulsifier including a blend of relatively more hydrophilic and relatively more hydrophobic non-ionic surfactants, an emollient, e.g., an oil, one or more thickeners, heating reagents (oxidizing agent and reducing agent), and a post-foaming agent.

[0015] The compositions are provided in the form of an oil-in-water emulsion that is divided into two phases, (a) an oxidant phase containing the oxidizing agent and (b) a reductant phase containing the reducing agent. Any ingredients that could be easily oxidized by the oxidizing agent during the product shelf life are included in the reductant phase. These two phases are maintained separate in the packaging of the shaving gel composition, as will be discussed further below, and are mixed during or after dispensing. When the two phases are mixed, an exothermic reaction occurs that heats the gel. If the exothermic reaction generates an acid that might tend to irritate the user's skin, the reductant composition generally includes a neutralizing agent to neutralize this acid.

[0016] The ingredients of the composition will be discussed in detail below.

[0017] The blend of surfactants is selected to provide several functions. The surfactant blend functions as an emulsifier, solubilizer, detergent, and spreading or dispersing agent. First, the surfactants provide an emulsion that is stable during the shelf life of the product, allowing the product to be dispensed as a gel exhibiting little or no phase separation. Second, the surfactants provide lathering during post-foaming. Third, the surfactants are capable of providing a lather that will remain stable at elevated temperatures, i.e., the temperatures the gel will reach during heating, typically about 35 to 50° C. By “stable,” we mean that the lathered gel will not puddle in the user's hand or drip from the user's face, but will instead maintain substantially the same consistency before, during and after heating. The blend of surfactants is generally present in both the oxidant and reductant components, so that both components can be provided as stable emulsions that can be dispensed in gel form.

[0018] Suitable nonionic surfactants have hydrophilic groups, e.g., hydroxyl groups and ether linkages from polyhydric alcohols and polyoxyethylene chains. Because they are stable in the presence of mild acids and alkalis, nonionic surfactants provide flexibility of formulation that is generally not possible using soaps.

[0019] Suitable surfactant blends may include, as a relatively more hydrophilic surfactant, a long chain fatty alcohol ethoxylate, i.e., an ether of fatty alcohol and polyethylene oxide having a polyethylene oxide chain length of at least 15. Preferred long chain fatty alcohol ethoxylates generally have a fatty alcohol chain length of C₁₂ to C₂₄, a degree of unsaturation of 0-2, and a polyethylene oxide chain length of 20-100 ethylene oxide units. Thus, preferred long chain fatty alcohol ethoxylates have the general formula:

CH₃—(CH₂)_(x)—CH₂—O—(CH₂—CH₂—O—)_(y)—CH₂OH, Where X=10-20, Y=19-99

[0020] A preferred long chain fatty alcohol ethoxylate is Steareth 100 (100 indicates the polyethylene oxide chain length). Other long chain fatty alcohol ethoxylates may be used, e.g., Ceteth 100. Surfactants with an HLB range of 8-18 are generally preferred, to provide a translucent to clear solution and good oil-in-water emulsification.

[0021] Suitable surfactant blends may include, as a relatively hydrophobic component, a relatively shorter chain length fatty alcohol ethoxylate, i.e., a fatty alcohol ethoxylate having a polyethylene oxide chain length of less than about 25. Preferred short chain length ethoxylates generally have a fatty alcohol chain length of C₁₂ to C₂₄ and a polyethylene oxide chain length of 15-25, for example Ceteth 20 and Steareth-20.

[0022] The two surfactants are included in a ratio that provides the desired aesthetic and performance properties to the gel. Including more of the relatively hydrophobic surfactant will generally provide a stiffer gel with higher clarity but less lathering ability. On the other hand, including more of the relatively hydrophilic surfactant will provide greater lathering ability but may reduce clarity and produce a softer gel. The hydrophobic portion is generally made up of alkyl groups whilst the hydrophilic portion is provided by ethylene oxide units. Thus, the relative amounts of the two surfactants may be adjusted to obtain a desired balance of properties. For a clear gel having good consistency and lathering, a suitable ratio of the hydrophobic surfactant to the hydrophilic surfactant would generally be in the range of 1:1 to 1:3. The total amount of the two surfactants in the composition is generally in the range of 5 to 15%, preferably 8 to 12% by weight. Including too high a level of the surfactants may result in a gel that is too stiff and thus does not transition quickly to a foam when spread on the skin, while including too low a level of the surfactants may result in a gel that is not sufficiently stiff and thus may phase separate in the container, or may come out of the container as a foam. Two fatty alcohol ethoxylates in combination serve to stabilize the oil droplets, which are distributed in the water phase and in which the blowing gas resides.

[0023] It is preferred that the compositions include emollients, to provide desirable cosmetic properties. The oil phase of the emulsion may include any desired emollient that is safe for use in a shaving gel, is compatible with the other ingredients of the composition, and provides the desired aesthetics and in-shave lubricity. Suitable emollients include mineral oil, petrolatum, squalane/squalene, hydrogenated/unsaturated polyisobutene and mixtures thereof. These emollients are suitable for use with the surfactant blends discussed above. Preferably, the composition contains from about 1 to 15% of the emollient, more preferably about 3 to 12% and most preferably about 4 to 8%, by weight of the composition. The emollient is provided in both components. When such emollients are included, it is generally preferred that the surfactants discussed above have an HLB in the range of 8-13 and that the surfactants be used in the ratios discussed above. Non-volatile paraffinic emollients, such as mineral oil, generally also aid in gelling the composition. The term “non-volatile” means that these materials are liquid at room temperature and have a relatively high boiling point (>100° C.).

[0024] The thickener is included to improve the consistency and stability of the gel, as well as to adjust its viscosity. The thickener also generally provides body to the foam. A preferred thickener is a fatty alcohol. Suitable fatty alcohols have a chain length of 12-22, and a degree of unsaturation of 0-1. Suitable fatty alcohols include, e.g., myristyl alcohol, lauryl alcohol, cocoyl alcohol, cetyl alcohol, cetearyl alcohol, oleyl alcohol, stearyl alcohol and behenyl alcohol. Generally the composition includes about 1 to 10% by weight of a fatty alcohol thickener.

[0025] In addition, the composition may include other suitable water-soluble thickeners, including, for example, hydroxyalkyl cellulose polymers such as hydroxyethyl cellulose and hydroxypropyl cellulose (sold under the trademarks “Natrosol” and “Klucel” respectively), carboxymethyl cellulose, and cellulose methyl ether (sold under the trademark “Methocel”). Other suitable thickeners include other polysaccharides, e.g., Xanthan gum, guar gum, modified starch, carageenan, and mixtures thereof.

[0026] The thickener may also include an ethoxylated or non-ethoxylated fatty ester such as PEG-150 distearate, PEG-150 pentaerythrityl tetrastearate, pentaerythrityl tetraisostearate, pentaerythrityl tetrastearate, and mixtures thereof. To formulate a solid gel with good visco-elastic properties, it is generally preferable to include both aqueous thickeners (e.g., polysaccharide polymers, polyethylene oxides) and non-aqueous thickeners (e.g., fatty alcohols, pentaerythrityl fatty esters).

[0027] The thickener is typically included in an amount sufficient to provide a desired consistency and stability. Generally, the composition includes the thickener at a level of about 0.01% to 10%, preferably about 0.1% to 7%, by weight of the composition. Thickeners are included in both components of the composition. It is preferred that the thickener used in the oxidant be stable in the presence of an oxidizing agent. A suitable thickener for this purpose is poly(vinyl alcohol).

[0028] As discussed above, the heating reagents generally include an oxidizing agent and a reducing agent. Suitable oxidizing agents include peroxides, e.g., hydrogen peroxide, peroxomonosulfate, peroxodisulfate, urea hydrogen peroxide, and t-butyl peroxide.

[0029] Suitable reducing agents are those that will react with the oxidizing agent when the two components of the formulation are mixed, to generate an exothermic reaction. Suitable reducing agents should also be safe for use on human skin in the amounts used in the formulation. The reducing agent may include, for example, thiosulfate and sulfite compounds, such as sodium sulfite, sodium thiosulfate, ammonium thiostilfate, potassium thiosulfate, and thiourea. Other suitable reducing agents include compounds with a thiourea backbone, such as 1,5 diethyl-2-thiobarbituric acid or its derivatives, or ascorbic acid. Mixtures of the above reducing agents, and other suitable reducing agents, may also be used.

[0030] Water is the major component of the composition and is used in sufficient quantities to solubilize the surfactant components and form the continuous phase of the emulsion, while providing a stable gel of suitable viscosity with desirable lathering and rinsing properties. It is added in a sufficient quantity (q.s) to bring the total of all components to 100%. The quantity of water in the composition typically falls within the range of about 55 to 90%, preferably about 60 to 85%.

[0031] The oxidizing agent and reducing agent are generally included in stoichiometric proportions, based on the redox reaction that will occur. The redox reaction of hydrogen peroxide with sodium thiosulfate is as follows:

2S₂O₃ ²⁻+H₂O₂S₄O₆ ²⁻+2OH⁻

[0032] In the presence of catalyst the reaction is as follows:

Na₂S₂O₃+4H₂O₂ Na₂SO₄+3H₂O+H₂SO₄

[0033] The total amount of the two components is selected to provide a desired level of heat and duration of the exothermic reaction. Preferably, the maximum temperature obtained by the gel during the reaction is from about 30 to 60° C., and this temperature is reached about 10 to 45 seconds after the two components are mixed (this is the temperature the gel reaches when the oxidant and reductant phase of the gel are mixed in a beaker in stoichiometric amounts that provide a total weight of 10 grams of the gel; when a typical amount of 5 to 8 grams of gel are applied to the skin, the actual temperature on the skin is typically about 28 to 45° C.). When the oxidizing agents and reducing agents described above are used, the composition generally includes about 2 to 10% of the oxidizing agent and about 2 to 10% of the reducing agent, in stoichiometric proportions.

[0034] To obtain the heat profile described above, it is generally necessary to include a catalyst in the composition. The catalyst is selected to catalyze the exothermic reaction, without deleterious effects on the skin or on the properties of the gel. The catalyst is generally included in the reductant component of the composition. Suitable catalysts for the oxidizing agents and reducing agents described above include sodium molybdate, potassium molybdate, ammonium molybdate, sodium tungstate, potassium tungstate, and mixtures thereof. The composition generally includes from 0 to 1.5% of the catalyst, by weight.

[0035] If the exothermic reaction generates an acid, as the reaction of the oxidizing and reducing agents discussed above will generally do, it is preferred that the composition also include a neutralizing agent. The neutralizing agent is selected and is provided in a sufficient amount so as to neutralize enough of the acid so that the composition will not irritate the user's skin. Preferably, substantially all of the acid is neutralized. Suitable neutralizing agents include, for example, triethanolamine, alkaline bicarbonates, oxides and hydroxides, e.g., calcium oxide, potassium bicarbonate, potassium hydroxide and sodium hydroxide. Generally, for the redox chemistries described above, the composition will include about 0.5 to 10% of such a neutralizer.

[0036] The shaving composition may include additional non-ionic and/or amphoteric co-surfactants, typically in an amount of about 1% to about 6%, preferably about 2% to about 5%, by weight.

[0037] Suitable non-ionic surfactants include the fatty esters of polyhydro alcohols (e.g. polyglyceryl mono oleate), polyoxyethylene fatty esters of glycerides and fatty amides, particularly the alkyl-substituted fatty amides. These surfactants will generally have about 6 to about 100, preferably about 20 to about 50, ethylene oxide units per molecule. Typical non-ionic surfactants include, for example, PEG-40 hydrogenated castor oil and decaglycerol monooleate. Suitable amphoteric surfactants include, for example, the betaines and sultaines such as cocoamidopropyl betaine, coco dimethyl carboxymethyl betaine, coco sultaine and the like. These amphoteric surfactants may tend to function as foam boosters and stabilizers, providing additional heat stability for the foam and preventing puddling. It is preferred that the composition include from about 0.2 to 1.0% of an amphoteric surfactant as a foam booster.

[0038] Other suitable co-surfactants include sodium lauroyl lactylate, sodium caproyl lactylate, and alkyl polyglucosides.

[0039] For thickening and/or increased lubricity, the shaving composition may also include a lubricious water soluble polymer, typically in an amount of about 0.005% to about 4%, preferably about 0.01% to about 1.0%, by weight. Such polymers will typically have a molecular weight between about 300,000 and 15,000,000 daltons. Suitable polymers include, for example, polyvinylpyrrolidone (PVP), PVP/vinyl acetate copolymer, polyethylene oxide, polyacrylamide, and mixtures thereof.

[0040] The post-foaming agent may be any volatile hydrocarbon or halohydrocarbon with a sufficiently low boiling point that it will volatilize and foam the gel upon application to the skin, but not so low that it causes the gel to foam prematurely. The typical boiling point of such an agent generally falls within the range of −20′ to 40° C. Preferred post-foaming agents are selected from saturated aliphatic hydrocarbons having 4 to 6 carbon atoms, such as n-pentane, isopentane, neopentane, n-butane, isobutane, and mixtures thereof. Most preferred is a mixture of isopentane and isobutane in a weight ratio (IP:IB) of about 1:1 to about 9:1, preferably about 2:1 to about 7:1, most preferably about 3:1. The post-foaming agent will normally be selected so as to provide a vapor pressure at 20° C. of about 3 to about 20 psig, preferably about 5 to about 15 psig. The post-foaming agent will be present in an amount to provide the shaving composition with a sufficiently rapid turnover—that is, transition from gel to foam when contacted with the skin—typically, in about 2 to about 30 seconds, preferably in about 5 to about 15 seconds. The post-foaming agent is generally included in both the oxidant and reductant components, and may be added to concentrates formed by pre-mixing the other ingredients of each component.

[0041] Although not necessary to forming a useful shaving composition, other cosmetic ingredients may be advantageously added to improve the application aesthetics and/or achieve other shave benefits. For example, the composition may include one or more of the following components: beard wetting agents, skin conditioning agents (vitamin precursors and derivatives such as e.g., vitamins A, C and E, aloe, allantoin, panthenol, alpha-hydroxy acids, phospholipids, triglycerides, botanical oils, amino acids), foam boosters, emollients (e.g., sunflower oil, fatty esters, squalane), humectants (e.g., glycerin, sorbitol, pentylene glycol), fragrances, colorants, antioxidants, preservatives, and other such ingredients.

[0042] The oxidant and reductant phases are maintained separate from each other until the product is dispensed. This may be accomplished using any desired type of two-component packaging, e.g., as described in U.S. Pat. Nos. 3,241,722, 3,454,198, and 6,250,505, and in co-pending U.S. Ser. No. 10/283,033, filed Oct. 29, 2002, the disclosures of which are incorporated herein by reference. Generally, suitable packaging includes a pressurized canister including two components, e.g., defined by two bags.

[0043] The gels described above may be formed using any suitable manufacturing process. An example of a suitable process is as follows. The thickeners are added to the water and allowed to hydrate over a period of time (30-60 minutes). The entire batch is then heated to 85-90° C. During the heating step, mineral oil, co-thickeners (Myristyl alcohol, PEG-150) and surfactants are added. The mixture is maintained at 85-90° C. with mixing for 30 minutes. Then the mixture is allowed to cool to room temperature. During the cooling phase, at 75° C., neutralizer is added. The preceding steps form a shave gel concentrate.

[0044] To form the reductant phase, actives such as sodium thiosulfate and sodium molybdate are added to the concentrate formed above, followed by the fragrance and dye, with mixing at 55° C.

[0045] To form the oxidant phase, an aqueous solution of hydrogen peroxide is added to the concentrate and mixed at 35-40° C.

[0046] At 35-45° C., each of the oxidant and reductant phases are blended with a post-foaming agent at the desired weight percentage range of 3-4.5%. The shave gel is then packaged in a two-component aerosol gel can, e.g., having a bag-in-bag assembly. It is preferable to place the oxidant phase in the inner side of the bag and the reductant phase in the outer side of the bag. Even if there is a breach in the bag, having the oxidant phase in the inner bag will generally ensure the integrity of the can.

EXAMPLE

[0047] Shave gels were manufactured according to the formulations shown in the following tables.

[0048] Oxidant Phase: SSEC-76-0 SSEC-107-0 SSEC-136-0 Ingredients Wt. % Wt. % Wt. % Water 66.03 64.32 65.66 Hydrogen peroxide, 35% 11.50 11.50 11.50 soln. Myristyl alcohol 6.90 6.90 6.40 Mineral Oil 6.00 6.00 6.00 Steareth-100 4.72 2.80 4.72 Ceteth-20 4.72 8.00 4.72 PEG-150 distearate 0.08 0.08 — Poly(vinyl pyrrolidone) 0.05 — — [Luviskol K-90 Powder] Poly(vinyl pyrrolidone) 0.40 0.50 [Luviskol K-90], 20% solution Cetearyl Alcohol (1:1) — — 0.50 SSEC-138-0 SSEC-141-0 Ingredients Wt. % Wt. % Water 65.56 64.05 Hydrogen peroxide, 35% soln. 11.50 11.50 Myristyl alcohol 6.00 6.40 Mineral Oil 6.00 6.00 Steareth-100 4.72 4.00 Steareth-20 4.72 5.50 PEG-150 distearate 0.10 0.05 Poly(vinyl pyrrolidone) [Luviskol 0.50 0.50 K-90], 20% solution Cetearyl Alcohol (1:1) 0.90 0.50

[0049] Reductant Phase: SSEC-85-1599 SSEC-89-1599 SSEC-90-1599 Ingredient Wt. % Wt. % Wt. % Water 64.43 67.00 67.02 Sodium thiosulfate pentahydrate 6.50 6.50 6.50 Myristyl alcohol 6.00 6.00 6.00 Mineral oil, 65/75 7.50 5.00 5.00 Steareth-100 2.80 2.80 2.80 Ceteth-20 8.00 8.00 8.00 PEG-150 distearate 0.15 0.08 0.08 WSR Sentry Coagulant (PEO) 0.02 0.02 — Puregel B994 — — 0.50 Vanzan NF-C (Xanthan Gum) 0.50 0.50 — Natrosol 250 HR 0.50 0.50 0.50 Sodium Molybdate dihydrate 0.20 0.20 0.20 Potassium bicarbonate 1.20 1.20 1.20 Fragrance, GPC-1599 1.50 1.50 1.50 Ritafactant 122 MS 0.50 0.50 0.50 FD & C Blue 1% dye 0.20 0.20 0.20 SSEC-91-1599 SSEC-98-1599 SSEC-101-1599 Ingredient Wt. % Wt. % Wt. % Water 66.72 60.42 59.38 Sodium thiosulfate pentahydrate 6.50 6.50 6.50 Myristyl alcohol 6.00 6.00 7.00 Mineral oil 5.00 5.00 6.00 Steareth-100 2.80 2.80 2.80 Ceteth-20 8.00 8.00 — Steareth-20 — — 8.00 PEG-150 distearate 0.08 0.08 0.20 Puregel B994 0.50 0.50 — Vanzan NF-C (Xanthan Gum) — — — Promidium CO 0.50 Natrosol 250 HR 0.50 0.50 — Superfloc N-300 LMW Flocculant — — 0.02 Sodium Molybdate dihydrate 0.50 1.00 0.70 Potassium bicarbonate 1.20 — — Triethanolamine, 99% — 7.00 7.00 Fragrance, GPC-1599 1.50 1.50 1.50 Ritafactant 122 MS 0.50 0.50 — FD & C Blue 1% dye 0.20 0.20 0.40 SSEC-103-1599 SSEC-149-1599 SSEC-150-1599 Ingredient Wt. % Wt. % Wt. % Water 59.78 59.70 57.93 Sodium thiosulfate pentahydrate 6.50 6.50 6.50 Myristyl alcohol 7.00 6.50 6.00 Mineral oil 6.00 5.00 7.00 Steareth-100 4.60 4.60 2.80 Steareth-20 5.70 5.70 8.00 PEG-150 distearate 0.30 0.30 0.15 Promidium CO 0.50 0.50 — WSR Sentry Coagulant — — 0.02 Natrosol 250 HHR 0.20 0.40 — Natrosol 250 HR — — 0.50 Vanzan NF-C 0.50 Superfloc N-300 LMW Flocculant 0.02 — — Cetearyl alcohol 50/50 0.90 — Polyox WSR 205 0.30 — Sodium Molybdate dihydrate 0.70 0.70 0.70 Triethanolamine, 99% 7.00 7.00 7.00 Fragrance, GPC-1599 1.50 1.50 1.50 FD & C Blue 1% dye 0.20 — 0.40 Ritafactant 122MS 0.50 FD & C GY-3 0.40

[0050] Any of the reductant phases described above can be used with any of the oxidant phases.

[0051] When dispensed, the formulations described above create a dense foam, comparable to the type of foam that is generally observed when using soap-based post-foaming shaving gels. When the oxidant and reductant phases were mixed in stoichiometric proportions to provide an amount of gel suitable for use in shaving (approximately 8 grams), the formulations provided a pleasant warming sensation. The foam did not collapse with the heat and lasted for the entire period of shaving.

[0052] The following graph depicts a typical skin temperature profile that is representative of the skin temperature profiles observed when applying the formulations described above.

[0053] Other embodiments are within the scope of the following claims. 

What is claimed is:
 1. A shaving composition in the form of a post-foaming gel comprising, water, a water-dispersible surface active agent capable of forming a lather, a volatile self-foaming agent, and heating reagents selected to provide an exothermic reaction during use of the shaving composition.
 2. The shaving composition of claim 1 wherein the gel comprises an oil-in-water emulsion including a non-ionic emulsifier.
 3. The shaving composition of claim 2 wherein the heating reagents include an oxidizing agent and a reducing agent, and the shaving composition is provided in the form of an oxidant component and a reductant component that are maintained separate until the shaving composition is dispensed by a user.
 4. The shaving composition of claim 3 wherein the oxidizing agent comprises a peroxide.
 5. The shaving composition of claim 4 wherein the reducing agent is selected from the group consisting of thiosulfate and sulfite compounds, compounds with a thiourea backbone, and mixtures thereof.
 6. The shaving composition of claim 2 wherein the non-ionic emulsifier comprises a fatty alcohol ethoxylate with relatively long polyethylene oxide chain.
 7. The shaving composition of claim 6 wherein the non-ionic emulsifier further comprises a fatty alcohol ethoxylate with relatively shorter polyethylene oxide chain.
 8. The shaving composition of claim 7 wherein the fatty alcohol ethoxylates with relatively longer and relatively shorter polyethylene oxide chains are provided in a ratio in the range of from about 1:1 to 1:3.
 9. The shaving composition of claim 2 wherein the non-ionic emulsifier comprises a blend of a relatively more hydrophobic surfactant and a relatively more hydrophilic surfactant.
 10. The shaving composition of claim 1 wherein the shaving composition is substantially free of soaps and ionic surfactants.
 11. The shaving composition of claim 1 further comprising an emollient.
 12. A post-foaming shave gel product comprising, a two-component container having two separate chambers; disposed in one chamber, an oxidant component comprising a first post-foaming shave gel base including an oxidizing agent, and disposed in the other chamber, a reductant component comprising a second post-foaming shave gel base including a reducing agent; at least one of the post-foaming shave gel bases including water, a water-dispersible surface active agent capable of forming a lather, and a volatile self-foaming agent.
 13. The post-foaming shave gel product of claim 12 wherein the first and second post-foaming shave gel bases are provided in the form of oil-in-water emulsions.
 14. The post-foaming shave gel product of claim 12 wherein the first and second post-foaming shave gel bases include a non-ionic emulsifier.
 15. The post-foaming shave gel product of claim 14 wherein the non-ionic emulsifier comprises a fatty alcohol ethoxylate with long polyethylene oxide chain.
 16. The post-foaming shaving gel product of claim 15 wherein the non-ionic emulsifier further comprises a fatty alcohol ethoxylate with relatively shorter polyethylene oxide chain.
 17. The post-foaming shaving gel product of claim 16 wherein the fatty alcohol ethoxylates with relatively long and relatively shorter polyethylene oxide chains are provided in a ratio in the range of from about 1:1 to 1:3.
 18. The post-foaming shaving gel product of claim 14 wherein the non-ionic emulsifier comprises a blend of a relatively more hydrophobic surfactant and a relatively more hydrophilic surfactant.
 19. The post-foaming shaving gel product of claim 12 wherein the first and second post-foaming shave gel bases are substantially free of soaps and ionic surfactants. 